The present invention relates to methods and apparatus for inspecting threaded objects and holes.
The inspection of threades and threaded parts is a major problem in modern industry. There are generally two classes of these sorts of inspections that are required. One is to make sure that machines which tap threaded holes in parts such as cylinder heads, engine blocks, exhaust manifolds etc., are indeed performing the job correctly and that the taps have not broken, loaded up, etc. If these things occur, a substantial loss of productivity occurs and additional costs are often incurred down the line for repair.
The second major application of threaded part inspection is inspection of fasteners, bolts, nuts, and other types of items such as rocker studs, etc. In these cases, the ability of the fastener to perform its function and maintain a correct joint can be dependent on the threaded quality. In many cases, the problem does not require measurement of exact threaded dimension: it is sufficient to determine whether or not the threades are present where required.
The invention here disclosed is a simple means of providing inspection of threads and, in particular, threads in blind holes or through holes and is particularly aimed at inspection of nuts and threaded holes in engine components. Also disclosed are means for inspecting holes drilled and otherwise provided in machined parts whose incorrect depth or total absence can lead to loss of productivity and warranty repair or safety related recalls due to lubrication failure, etc.